A technology for capturing and viewing a 360 degree full-dome video has been researched and developed. For example, the technology is mainly applied to a field of entertainment video such as sports or concert relay, intangible cultural heritage or education content, or the like. The technology is gradually applied to services providing virtual visit and experience of a real space.
A viewer can freely select a viewpoint position or a line-of-sight direction, enjoying a full-dome video. For example, a head mount display which is used by being mounted to the viewer's head can be used to view a full-dome video. The movement of the viewer's head is detected to display the full-dome video while changing the viewpoint position or the line-of-sight direction on the basis of a result of the detection. Therefore, the viewer can have experience as if he/she actually visit and experience a space where the full-dome video is captured.
For example, a head mount display system is proposed which includes an imaging system configured to capture a wide-angle image having a wider field of view than that of the image actually displayed, and extracts and displays an image to be displayed which a user should view, on the basis of information about the position of the user's head detected by a rotation angle sensor (e.g., see Patent Document 1).
Furthermore, a mobile camera device is proposed which includes a head mount display configured to be mounted to a viewer's head, an angular velocity sensor configured to detect the rotation of the viewer's head, and a camera direction calculation device configured to calculate a rotation angle of the viewer's head and turn right and left cameras (e.g., see Patent Document 2). In addition, a mobile camera system is proposed which includes a control server to manage the positions of a plurality of mobile camera devices installed on a mobile body, such as a vehicle, and images acquired therefrom in an image database, in which the control server searches the image database for an image satisfying an imaging request transmitted from a terminal device or acquires, from a new mobile camera device, an image satisfying the imaging request, and transmits the image to the terminal device (e.g., see Patent Document 3).